The present invention relates to a patient-support assembly for a patient-support apparatus, and particularly, to a patient-support assembly for a thermal support apparatus such as an infant warming device. More particularly, the present invention relates to a tilting mechanism and an X-ray tray that are included in the patient-support assembly.
Thermal support devices, such as infant warmers and incubators, having a chamber and various systems that maintain the chamber at a controlled temperature and humidity to facilitate the development of a premature infant are known. Conventional thermal support devices include a mattress for supporting the infant in the chamber and devices for adjusting the elevation and inclination of the mattress relative to the rest of the thermal support device. It is desirable for devices that adjust the elevation and inclination of the mattress to do so in a smooth manner. It is also desirable for devices that adjust the elevation and inclination of the mattress to be made from a small number of basic components to minimize cost and to simplify cleaning and service, when needed.
Some conventional thermal support devices include x-ray trays that support cassettes of x-ray film beneath the infant when x-rays are to be taken, thereby eliminating the need to transfer the infant to another support device to have x-rays taken. It is desirable for x-ray trays to be accessible from either side of the thermal support device so that cassettes of x-ray film can be loaded onto the x-ray tray from either side of the thermal support device.
According to the present invention, a patient-support apparatus includes a base and a patient-support assembly supported above the base. The thermal support assembly includes a patient-support deck having longitudinally spaced-apart ends and an elevation mechanism for moving one of the ends of the patient-support deck relative to the other of the ends and relative to the base. In a preferred embodiment, the elevation mechanism includes a transversely-extending threaded shaft, a pair of blocks threadedly coupled to the shaft, and a linkage coupled to the pair of blocks and extending upwardly therefrom to support the end of the patient support deck to be moved by the elevation mechanism. The pair of blocks move transversely in response to rotation of the threaded shaft and the linkage is configured to move the end of the patient-support deck relative to the base in response to transverse movement of the blocks.
In preferred embodiments, the thermal support apparatus includes such an elevation mechanism at each of the ends of the patient-support deck. The elevation mechanisms are independently operable to move the patient-support deck to Trendelenburg and reverse Trendelenburg positions. In addition, the elevation mechanisms are operable to position the patient-support deck in an infinite number of positions between the Trendelenburg and reverse Trendelenburg positions.
A first portion of the threaded shaft of each elevation mechanism is formed to include a right-handed thread and a second portion of the threaded shaft of each elevation mechanism is formed to include a left-handed thread. In addition, each of the blocks of the pair of blocks includes a drive block portion and a nut plate formed to include a first aperture having a right-handed thread and a second aperture having a left-handed thread. The orientation of the nut plates relative to the respective drive block portions depends upon which portion of the threaded shaft the respective block is to be mounted. This "reversible" nut plate arrangement allows the drive blocks and the nut plates to be identically constructed and then assembled together in the appropriate manner.
The linkage of each elevation mechanism includes a first link, a second link, and a deck-engaging link. Each of the first and second links has a lower end that pivotably couples to a respective drive block portion and an upper end that pivotably and slidably couples to the deck-engaging link. The first link is pivotably coupled to the second link in a crossing or "scissors" arrangement. Each deck-engaging link supports the end of the patient-support deck to be moved by the respective elevation mechanism. In addition, each deck-engaging link is formed to include first and second slots and the upper ends of the respective links are coupled to the deck-engaging links at the respective slots. Each elevation mechanism includes an idler arm having an upper end coupled to the respective deck-engaging link and a lower end pivotably coupled to the respective first link to prevent transverse movement of the deck-engaging link relative to the respective first and second links.
Each elevation mechanism includes a pair of knobs and each knob is coupled to an end of the respective threaded shaft. Each knob includes a knob body and a crank handle coupled to the knob. In use, each knob is rotated to make minor adjustments to the elevation mechanism and the crank handle is folded out relative to the knob body to a use position where it is used to quickly rotate the knob body and threaded shaft to make major adjustments to the elevation mechanism. A spring is interposed between each knob and the respective threaded shaft to provide shock absorption therebetween. The springs allow each knob to move transversely inwardly toward the respective shaft if the knob is inadvertently bumped. After a particular knob is bumped, the respective spring biases the knob outwardly back into its normal position.
According to the present invention, the thermal support apparatus includes an x-ray tray coupled to the patient-support deck for sliding movement beneath a mattress carried by the patient-support deck. A link couples the x-ray tray to the patient-support deck. The x-ray tray is movable between a use position underlying the mattress, a first load position in which a portion of the x-ray tray extends beyond a first side of the patient-support deck, and a second load position in which a portion of the x-ray tray extends beyond a second side of the patient-support deck. The patient-support deck is formed to include a first stop adjacent to the first side and a second stop adjacent to the second side. When the x-ray tray is in the first load position, the link engages the first stop and when the x-ray tray is in the second load position, the link engages the second stop.
The patient-support deck includes a slot extending between the first and second stops along a generally bell-shaped path and the x-ray tray is formed to include an aperture. The link is formed to include a downwardly-extending first end disk received in the slot for sliding movement relative to the patient-support deck and an upwardly-extending second end disk received in the aperture for pivoting movement relative to the x-ray tray. The bell-shaped path of the slot causes the link to pivot through approximately one hundred eighty degrees relative to the x-ray tray as the x-ray tray is moved between the first and second load positions. Engagement between the first end disk of the link and the first and second stops prevents the x-ray tray from moving past the respective first and second load positions.
The base of the thermal support apparatus supports a platform tub having an upwardly-facing platform surface and four walls extending upwardly therefrom to define an interior region above the platform surface. The patient-support assembly is supported by the platform surface. When the patient-support deck and x-ray tray are positioned to lie inside the interior region of the platform tub, the x-ray tray is inaccessible. When the patient-support deck and x-ray tray are positioned to lie above the interior region of the platform tub, the x-ray tray is accessible to be moved between the use position and each of the first and second load positions.
Embodiments of the present invention, therefore, comprise a base and a patient-support assembly supported above the base. The patient-support assembly includes a patient-support deck and an elevation mechanism for moving one of the ends of the patient-support deck. The elevation mechanism includes first and second links coupled together at their middle portions, a deck-engaging link coupled to upper ends of the first and second links and arranged to support the end of the patient-support deck, and a driver coupled to lower ends of the first and second links. The driver is operable to move the lower ends of the first and second links toward one another to raise the deck-engaging link and away from one another to lower the deck-engaging link. The deck-engaging link includes an upwardly-facing surface and the patient-support deck includes a downwardly-facing surface that engages the upwardly-facing surface to provide for pivoting and sliding movement of the patient-support deck relative to the deck engaging link. An x-ray tray is coupled to the patient-support deck by a link. The patient-support deck is formed to include first and second stops. When the link engages the first stop the x-ray tray is in a first load position extending beyond a first side of the patient-support deck and when the link engages the second stop the x-ray tray is in a second load position extending beyond a second side of the patient-support deck.
Additional features and advantages of the invention will become apparent to those skilled in the art upon consideration of the following detailed description of a preferred embodiment exemplifying the best mode of carrying out the invention as presently perceived.